From mboxrd@z Thu Jan 1 00:00:00 1970 From: Henrik Austad Subject: Re: [RFC] AVB - network-based soundcards in ALSA Date: Wed, 28 May 2014 11:43:18 +0200 Message-ID: <20140528094318.GC26498@austad.us> References: <20140526130352.GA17414@austad.us> <5384C37E.8060404@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-lb0-f180.google.com (mail-lb0-f180.google.com [209.85.217.180]) by alsa0.perex.cz (Postfix) with ESMTP id 8E6672654DF for ; Wed, 28 May 2014 11:47:46 +0200 (CEST) Received: by mail-lb0-f180.google.com with SMTP id p9so5535341lbv.25 for ; Wed, 28 May 2014 02:47:46 -0700 (PDT) Content-Disposition: inline In-Reply-To: <5384C37E.8060404@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Pierre-Louis Bossart Cc: Takashi Iwai , hansverk@cisco.com, alsa-devel@alsa-project.org, haustad@cisco.com List-Id: alsa-devel@alsa-project.org On Tue, May 27, 2014 at 11:55:26AM -0500, Pierre-Louis Bossart wrote: > > >This reminds me of the talk Pierre gave in LPC at San Diego a couple > >of years ago. Although his topic was more about the audio time > >accounting, the framework mentioned at that time would fit with this > >scenario? > > Yes it is related but the overall architecture on a first pass of > reading seems different: the ideas we presented were more along the > lines of letting every subsystem provide an accurate accounting of > time and have some userspace parts see and compensate the difference > between system, network, audio, video, clocks. Any documents/talks available for this? I found "Audio/system time alignment" from Plumbers 2012 (link at the bottom), is that the one? I see that this also covers AVB, but places everything AVB-related in userspace and then lets the application tie everything together. What was the design-rationale for this? To turn it around; our idea of placing this in the kernel was - easier to integrate with v4l - single interface (ALSA) for userspace to play audio - easy access to NIC internals to ship off frames and whatnot. what we found to be a pretty neat solution Did we miss something crucial? > very interesting topic and RFC, thanks for posting this. Thanks for providing feedback! :) http://www.linuxplumbersconf.org/2012/wp-content/uploads/2012/11/2012-lpc-audio-time-alignment-bossart.pdf -- Henrik Austad